Ink thinner or vehicle



Patented June 9, 1936 UNITED STATES INK THINNER OR VEHICLE Charles P.Shaw, Detroit, Mich assignor to Detroit Moulding Corporation, Detroit,Mich.

No Drawing. Original application July 28, 1933,

Serial No. 682,628. Divided and this application June 15, 1934, SerialNo. 730,754

1 Claim.

This application is a division of my application, Serial No. 682,628,filed July 28, 1933, now U. S. Patent No. 1,989,250, for Offset printinginks.

The main object of this invention is to provide a thinner or vehicle foroffset printing inks and the like.

Objects relating to details and economies of my invention will appearfrom the description to follow. The invention is defined and pointed outin the claim.

The printing plate is made plancgraphic by the half-tone process withthe design in relief. This is inked by a suitable machine or apparatusor by passing an ink roller over the plate, the ink not being forceddown into the recesses, but remaining on the relief or high parts of theplate. A rubber or composition transfer roller is then run over theplate and the design transferred to the panel or object to beornamented.

In this method of offset printing, with surface printing plates asdistinguished from intaglio plates, especially with regard to decoratinggarnish moldings, the method of or agent for producing the oilsetprinting ink is of prime importance. The thinner the ink with asufficient color, the better the print. Thinned ink readily lifts fromthe plate and readily releases from the printing roll. The ink must laydownperfectly and yet not be so thin as to fill up the printing plate.

Oil added to the ink will allow it to release from the printing roll,but if used alone makes the ink too thin, fills up the plate and greatlycuts the color of the print. Greasy compounds aid in making the ink laydown and do not cut the color. However, a large amount of such compoundsare required for satisfactory results, and further, there is a tendencyfor them to slur the printing.

I provide a thinner which combines the advantages of oil and greasycompounds, but which eliminates their disadvantages. I add to the offsetprinting ink a thinner containing the following ingredients by weight:

' Percent Castor oil 1.8 02-; 15.9 Colorless 00 litho varnish 2.5 oz22.1 Stearine 3.0 oz 26.8 Turpentine 4.0 oz 35.4

The castor oil, varnish, and stearine are dissolved in the turpentineand the ingredients are combined by the use of heat. Sufficient thinneris added to the offset printing ink until the lat ter is reduced to theproper consistency.

While any commercially available offset printing ink may be used with mythinner, I prefer to use offset printing ink containing by weightpigment 35% to 40% and vehicle 65% to 60%. The pigment may be carbonblack and the vehicle a heavy bodied linseed oil with a drier of therosin type. Offset printing ink of this character may be readily boughtor it may be duplicated by any ink manufacturer having facilities forgrinding in pigments. In the case of black ink, the weight of thepigment is about 35% and the vehicle 65%. In the case of brown ink, thepigment runs up to 40% and the vehicle 60%. The vehicle itself is from25% to 30% of the total weight, heavy bodied linseed oil, and 35% of thetotal weight, varnish.

Summarizing the analyses of the offset printing ink:

Black Brown Percent Percent Oil 25 35 35 Pigment 35 40 ing ink resultsin an ink which is of such character that a sufiicient quantity thereofis held on the high point or design of the relief printing plate so thatan effective transfer is made possible and that very good results areproduced.

The ink is especially useful in the ornamenting of metal with imitationwood graining. The plate is prepared from a photograph by the halftoneprocess and with the graining design in relief. The plate is inked withthe special ink by passing an inking roller over the plate, the ink notbeing forced down into the recesses, but remaining on the relief or highparts of the printing plate. A pick-up or transfer roller is then runover the inked plate and the graining design transferred to the panel orsurface to be ornamented.

The character of the special ink is such that it is held on the reliefor high part of the plate without filling the same and readily releasesfrom the transfer or printing roll and the plate. My thinner producesthese advantages without cutting the color of the offset printing inkand without slurring the printing. These characteristics and advantagesare highly desirable in the offset printing of delicate grainingeffects.

Having thus described my invention, what I claim as new and desire tosecure by Letters Patent is:

An ink thinner or vehicle comprising 15.9% castor oil, 22.1%lithographic varnish, 26.6% stearine, and 35.4% turpentine.

CHARLES P. SHAW.

